1. Field of the Invention
This invention relates to a method and apparatus for increasing Vitamin D content in mushrooms by exposing the mushrooms to a broad spectrum of light for up to one second, using an electric glow discharge lamp.
2. Description of the Prior Art
The two major forms of Vitamin D are Vitamin D2 and D3. Vitamin D2 is not produced by the human body and is only derived from fingi and plant sources. Vitamin D3 is produced in human skin through exposure to sunlight. The benefits of Vitamin D are numerous and deficiency in the vitamin in humans can lead to several diseases. Because human exposure to sunlight for prolonged periods is impractical, in order to receive the benefits and overcome potential deficiencies in Vitamin D, there is a need for a method and an apparatus to increase Vitamin D2 in mushrooms.
Commercially grown mushrooms contain very low levels of Vitamin D2, typically less than 4-10%. Mushrooms, however, naturally contain ergosterol, a biological precursor to Vitamin D2. Research shows that ergosterol in several species of mushrooms converts to Vitamin D2 when exposed to UV light. White button mushrooms, brown portobello mushrooms, shiitake mushrooms, and oyster mushrooms are some types of mushrooms known to show a Vitamin D2 response when exposed to UV light. With sufficient duration and exposure, the level of Vitamin D2 in these and other mushroom species can exceed 400 IU/84 g of mushrooms, equating to 100% of the current recommended Daily Value for Vitamin D in the United States.
To increase Vitamin D level in mushrooms, certain methods in the background art require mushroom exposure to UV light for extended periods to achieve a significant increase in the level of Vitamin D. In one method, exposure times from 1 hour to 24 hours were required. In other methods, 20 minutes to 60 minutes of exposure time were required.
Commercial mushroom packaging equipment processes up to 180 individual packages of mushroom per minute or three individual packages per second. Thus, the long exposure times of the background art are impractical and are not feasible for commercial mushroom handling. Hence, there remains a need for a method to increase the Vitamin D content in mushrooms that is practical and feasible for use with commercial mushroom packaging equipment.